Search

Póster presentado en EGU 2019, Viena (Austria) 7 al 12 de abril de 2019. Puede ver el Abstract en https://meetingorganizer.copernicus.org/EGU2019/EGU2019-9604.pdf, Due to their extraordinary properties, Actinobacteria can thrive in extreme environments, such as limestone caves, lava tubes and stone monuments. They grow forming microbial mats and speleothems on the walls and ceilings of caves, ranging from extensive coatings to small colonies (Riquelme et al. 2015). Their colour includes yellow, tan, orange, grey, pink and white. Recently, we have found abundant yellow and white-coloured bacterial mats coating the cave walls and secondary mineral deposits (speleothems) of lava tubes from La Palma Island, Canary Islands, Spain (Gonzalez-Pimentel et al. 2018) and Mount Etna in Catania (Sicily, Italy). Field Emission Scanning Electron Microscopy (FESEM) of the coloured microbial mats revealed abundant Actinobacteria-like cells, including a variety of filaments and spore structures with smooth surface ornamentation or profuse surface appendages. The DNA-/RNA-based analyses confirmed that these microbial mats are mainly composed of metabolically active Actinobacteria (Gonzalez-Pimentel et al. 2018). It is well known that Actinobacteria, mainly isolated from marine and soil ecosystems, are an important source of bioactive compounds, with Streptomyces ranking first with a huge number of bioactive secondary metabolites (Guo et al. 2015). These compounds, not only produced by Streptomyces but also by Bacillus, are very important to the industrial sector, such as pharmacology, biofuel and food industries, as well as to the conservation of stone cultural heritage, due to their antimicrobial properties (Silva et al. 2017). In the last decades, these sectors have intensified demands for exploring novel eco-friendly bioactive compounds, which stresses the need to investigate new groups of Actinobacteria from underexplored habitats. Yet, Actinobacteria from caves have not been the target of intensive screening for bioactive secondary metabolites. Hence, Actinobacterial-like microbial mats were collected and isolated from lava tubes in La Palma and Mount Etna to investigate their biotechnological potential. The screening of antimicrobial activity was based both on culture-dependent techniques using the agar diffusion assay and on metagenomics. Our study has howed that the strain Streptomyces sp. MZ0467C isolated from La Palma lava tube has antimicrobial activity against Microbacterium sp., Rhodococcus sp., Arthrobacter sp., Kocuria sp., Sphingomonas sp. and Paenibacillus sp. due to its ingenious adaptations and metabolic strategies to survive under extreme environmental conditions. This demonstrates that Actinobacteria from subterranean environments are promising sources of antibacterial compounds with interest for cultural heritage conservation., References: - Gonzalez-Pimentel JL. et al. 2018. Yellow coloured mats from lava tubes of La Palma (Canary Islands, Spain) are dominated by metabolically active Actinobacteria. Sci. Rep. 8, 1944. - Guo X. et al. 2015. Red soils harbor diverse culturable actinomycetes that are promising sources of novel secondary metabolites. Appl. Environ. Microbiol. 81, 3086-3103. - Riquelme C. et al. 2015. Actinobacterial diversity in volcanic caves and associated geomicrobiological interactions. Front. Microbiol. 6, 1342. - Silva M. et al. 2017. Green mitigation strategy for cultural heritage: Bacterial potential for biocide production. Environ. Sci. Pollut. Res. Int. 24, 4871-4881.

Póster presentado en el 20th EGU General Assembly, EGU2018, Proceedings from the conference held 4-13 April, 2018 in Vienna, Austria, p.1258, Val di Scerscen is located in the Central Italian Alps (Northern Lombardy), in the scenic setting of Valmalenco. This area is not very rich in caves (only about one hundred, among the over 4800 caves known in Lombardy). Here, oceanic metamorphic rocks, which where uplifted during the Alpine orogenesis, dominate the terrains. A thin lens of whitish dolomitic marbles belonging to the Austroalpine Margna Nappe hosts a few short caves, right at the end of the tongue of the Scerscen glacier, on the southern slopes of Piz Bernina. This glacier and its meltwater probably strongly contributed to the cave evolution. The most important caves, opening at about 2600 m asl, are: Veronica cave (length: 638 m), Morgana cave (348 m), and Tana dei Marsooi (77 m). These are typical epiphreatic caves with juvenile pattern and with adjustment to the water table (Audra and Palmer, 2013), according to the glacier evolution and to the valley incision. With the important retreat of the glacier during the Holocene, the processes of cave evolution have changed. The runoff provided by the glacier became less and less important and the drainage changed with the migration of the tongue of the ice cover. Today, the groundwater flow is mainly active during spring due to snow melting on a restricted catchment. The underground climate is characteristic of alpine caves, with a low mean temperature. Condensation-corrosion processes (James, 2013) presently have a major control on the morphology of the cave passages. The shape of walls and ceilings has changed with the aerosol circulations according to the gradient of temperature between the cave and the exterior. Consequently, condensating waters carved smooth reliefs, notches and bell holes. Ongoing studies are focused on: (i) long term processes (U/Th dating on calcite crusts, cosmonucleide dating on quartz pebbles); (ii) current physical processes of condensation-corrosion, comprising microclimatic monitoring and in situ exposure of limestone tablets, and (iii) assessment of microbially mediated corrosion. In this sense, vermiculations were collected in different sites of Morgana cave and studied by DNA-based analyses and field emission scanning electron microscopy at the IRNAS-CSIC (Seville, Spain). Thanks to the collaboration with Leica Geosystems Italy it has been possible to test, for the first time in a cave, two new 3D mapping instruments: the “BLK360” laser scanner, the smallest and lightest of its kind weighing only 1 kg, and the “Pegasus Backpack”, a mobile mapping system which allows making a 3D scan of the environment by simply walking around. The data allowed creating 3D models of the Veronica cave which can be used both for morphological analysis and for virtual tours with educational purposes.

Comunicación oral presentada en la S5.-Biodeterioration: Fundamentals, Present and Future Perspectives. Session in Honour of Prof. Cesáreo Sáiz Jiménez V del 3rd International Congress Science and Technology for the Conservation of Cultural Heritage.-- Technoheritage 2017 21-24th May 2017, Cádiz, Spain, Cave and catacombs microbiota and especially fungi are sensitive to organic input changes in their close environment. New input of organic sources (soil, dead animals and microorganisms, etc.) associated to favorable microclimatic parameters often lead to the overgrowth of fungi that may cover (colonize) a wide extension of available surfaces. The present research reports of a sudden fungal outbreak occurred in the corridor near the entrance of the Catacombs of SS. Marcellino and Pietro in Rome. A heavy fungal growth was observed one year after a restoration treatment that interested the walls of the entrance of the Catacombs and some artifacts placed in situ. Some marble slabs in fact, were restored and placed back into the walls. The colonization was observed only on the left side of the corridor around the marble slabs and on the vault. No growth was observed in the right side were similarly treated marbles slabs were placed. However, a high circulation of airborne fungal spores was observed. Mycological analysis were done on samples taken on the catacombs vault and side, as well as from soil and tree roots coming from upper ground above the catacombs. The combined use of microscopical, cultural and molecular tools showed that the vault and the left side of the corridor entrance were colonized by the brown Basydiomycetes Coniophora marmorata, that was able to form colonies with a diameter up to 57 cm, while secondary colonizations were due to different microfungi belonging to the genera Hypomyces chlorinigenus, Purpureocillium ilacinum, Acremonium persicinum, Penicillium spp. and Alternaria sp. The comparative analysis of roots and soils showed that fungi were present in all samples but a different distribution and diversity was observed. Due to the fast rate of growth of the fungi on the walls, a three steps emergency treatment was done with intervention on the environment, on the biodeteriogens and further by a close monitoring on monthly basis. Despite the successful intervention, it was clear that several causes could have created this fungal outbreak and for this reason, a continuous monitoring of the catacomb’s surfaces was planned. * Both Authors contributed equally in the isolation and characterization of fungal isolates.

Comunicación oral presentada en el Heritage Innovation Talks. T1. Biotecnología aplicada ao Património

Comunicación oral presentada en la European Geosciences Union General Assembly 2016 Vienna | Austria | 17–22 April 2016, Lava tubes have traditionally been considered of little interest from a mineralogical point of view. Recently, this type of volcanic caves has received particular attention because lava tubes have been described on Mars. Speleothems, or secondary mineral deposits in lava tubes are mainly composed of siliceous minerals. Coralloidtype speleothems are found either on basaltic cave walls or on the surface of other speleothems. Several authors attribute a microbially mediated origin to their formation. This type of speleothems was recorded within Royal Palm Cave of Santa Cruz Island in Galapagos Archipelago (Ecuador), a lava tube 600 m long, 5 to 15 m height and 2 to 10 m width. The Galapagos Islands are an archipelago of 19 volcanic islands located some 1500 km west of Ecuador, in the Pacific Ocean. These islands host one of the most biodiverse settings on Earth, studied by Charles Darwin. Beige and greyish small coralloids were collected in Royal Palm Cave and analysed by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDS), X-ray micro-computed tomography (micro-CT) and mineralogical analyses for morphological, 3D microstructural and compositional characterization, as well as for assessing microbe-mineral interactions and biogenicity. In addition, 16S rRNA gene analyses were performed to identify microbial communities associated with the coralloid-type speleothems. The coralloids showed internal compositional zonation along the growth direction of the speleothems, according to micro-CT data. Internal layering was clearly discernable by the differences in opacity of the distinct mineralogical phases to X-rays, being dominated by alteration products of siliceous composition, whereas more opaque phases, usually Ca-rich minerals, were dominant in the outermost part of the speleothems. X-ray diffraction and infrared spectroscopy reinforced that the first stage of deposition is mainly composed of opal A and clay minerals, whereas the final stage mainly consists of low crystalline calcite. FESEM-EDS analysis revealed mineralized bacterial filaments rich in Si on the coralloid samples, as well as minerals precipitation associated with extracellular polymeric substances (EPS), which serve as nuclei for preferential precipitation on the extracellular sheaths. This suggests that biological activity played a major role in the development of these speleothems. In addition, imprints of filamentous cells and microboring readily preserved on siliceous minerals were observed on the coralloid speleothems. These features are recognized as biosignatures valuable for astrobiology and may represent modern analogs of the fossil record of prokaryotes. DNA-based analyses showed that bacteria belonging to Actinobacteria (31%) Gemmatimonadetes (25%) and Proteobacteria (24%) phyla dominated in this cave ecosystem, followed by Acidobacteria, Firmicutes and Nitrospirae. Most of the identified phylotypes were affiliated to chemoautotrophs, including thermophilic bacteria such as Ferrithrix thermotolerans, and other mineral utilizing microorganisms like Aciditerrimonas ferrireducens, Desulfuromonas sp. and Desulfovibrio sp., indicating that Galapagos lava tubes host highly specialized subsurface biosphere dominated by microorganisms able to interact with minerals and promote biomineralization., This work has been supported by the project PC-65-14 from the Ministry of Environment of Ecuador. AZM acknowledges the support from the Marie Curie Fellowship of the 7th EC Framework Programme (PIEF-GA-2012-328689-DECAVE). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER funds for financial support

14 páginas, 7 figuras, 1 tabla, 23 referencias., [EN]: The importance of stone colonisation by microorganisms has led to an extensive literature on mechanisms and rates of physicochemical degradation of stone surface, both in laboratory and field contexts. Biological colonisation of a stone surface depends on intrinsic stone parameters like mineral composition, texture, porosity, and permeability, as well as on environmental parameters. In the present study, quantification of stone surface roughness and its relationship to epilithic colonisation was demonstrated for three types of limestones throughout non-destructive techniques, namely optical surface roughness instrument and digital image analysis. According to the roughness average (Ra) and mean roughness depth (Rz) determined for Ançã limestone, Lioz limestone and Lecce stone, it can be concluded that great surface roughness stones render them prone to microbial colonisation., [ES]: La colonización de la piedra por microorganismos ha generado una extensa literatura sobre los mecanismos y tasas de degradación fisicoquímica de las superficies pétreas, tanto en laboratorio como en estudios de campo. La colonización biológica de piedra de construcción depende de parámetros intrínsecos como son su composición mineral, textura, porosidad y permeabilidad, así como de parámetros ambientales. Este estudio demuestra la relación entre la rugosidad superficial de la piedra y la colonización epilítica, cuantificada en tres tipos de caliza mediante técnicas no destructivas: medida de la rugosidad superficial usando un perfilómetro óptico y análisis digital de imágenes. De acuerdo con la rugosidad media aritmética (Ra) y la amplitud media de rugosidad (Rz), determinadas para la caliza de Ançã, la caliza de Lioz y la piedra de Lecce, puede concluirse que las piedras con alta rugosidad superficial son más propensas a la colonización microbiana., Este estudio ha sido financiado por el Ministério da Ciência, Tecnologia e Ensino Superior, Portugal, con una beca postdoctoral (SFRH/BPD/63836/2009) y parcialmente financiado por CEPGIST-FCT subproyecto DECASTONE. Este trabajo recibió también financiación del Programa de Financiamento Plurianual de Unidades de Investigação da FCT, financiado por la Unión Europea, FEDER, y fondos nacionales de la República Portuguesa. Este es un trabajo del proyecto CONSOLIDER CSD2007- 00058. This study has been financed by the Ministério da Ciência, Tecnologia e Ensino Superior, Portugal, with a postdoctoral grant (SFRH/BPD/63836/2009) and partially financed by CEPGIST-FCT subproject DECASTONE. This work also received support from Programa de Financiamento Plurianual de Unidades de Investigação da FCT, financed by European Union, FEDER, and national budget of the Portuguese Republic. This is also a paper from the project CONSOLIDER CSD2007-00058.

Microorganisms (bacteria, green algae and fungi) may lead to complex problems in the conservation of cultural heritage assets due to their biodeteriorative potential. The biodeterioration phenomena observed on materials of cultural heritage is determined by several factors, such as climatic conditions, chemical composition and nature of the material itself, as well as biological colonizers. The combination of several non-destructive techniques is compulsory in the field of cultural heritage in order to develop and design new and effective conservation strategies to prevent, control and minimize the causes of decay. For instance, Confocal Laser Scanning Microscopy (CLSM) permits to detect the presence, the penetration depth and the spatial organization of different phototrophic microorganisms established on stone surfaces, as well as Digital Image Analysis allows quantifying the surface area covered by microorganisms without destroying the sample. In this study, these non-destructive instrumental analyses, together with in vitro chlorophyll a quantification, were applied in order to evaluate a new procedure of stone cleaning consisting of the application of secondary metabolites with biocide properties. Three different natural biocides were tested on Hontoria limestone samples, a biosparitic limestone used in many Spanish monuments, previously inoculated with a multi-species phototrophic culture. After 1 month of biofilm growth on Hontoria limestone samples, the following biocides were applied: - culture filtrates of the fungus Trichoderma harzianum T-22 strain, - culture filtrates of the bacterium Burkholderia gladioli pv. agaricicola ICMP (Bga) 11096 strain, - glycoalkaloids (GLAs) extract from unripe berries of Solanum nigrum. After one month of incubation, CLSM revealed that none of the treatments was efficient against all inoculated phototrophic species, probably due to different biocide resistance. This was also corroborated by spectrophotometric determination of chlorophyll a and digital image analysis. Among all treatments, the culture filtrates of T.harzianum and the GLAs’ extract showed higher biocidal efficiency than the Bga culture filtrate. It seems evident that non-destructive analysis and ecological cleaning methods can represent a innovative strategy for the protection of our stone cultural heritage. Further work on the biocidal effectiveness and durability of secondary metabolites in the medium and long-term is needed for the design of effective and sustainable treatments for minimizing or eradicate stone biodeterioration

Comunicación presentada en The Second International Congress on Science and Technology for the Conservation of Cultural Heritage was held in Seville, Spain, June 24-27, 2014, Sedimenlary rocks, and in particular, limeslone have been exlensively used in the Mediterranean Basin for the construction of monuments and hisloric buildings. In spite of its reputation of "eternal", limestone is not immune to weathering factors, such as biological decay or biodeterioration. Moreover, the high receptivity of the fragile calcium carbonate matrix results in a progressive deterioralion of the stone material and, over time, in the progressive loss of our cultural heritage. Biocides used lo prevent the growth of micro- and maeroflora responsible for stone biodeterioration are mostly based on the use of chemical methods. Nevertheless, they show restricted efficiency and can eause discolorations on the surtaces and even severe damages to the cultural assets. Recently, the use of natural biocides (derived from living organisms as microorganisms or planls) has attracted particular interest due to their low loxicity, specificily, effecliveness using small dose and fast decomposition rate when compared to synthetic biocides. The aim of this work is to assess the tertiary bioreceptivity of Hontoria limestone treated with secondary melabolites (organic compounds produced in certain stages of development in microorganisms and in specific parts of plants) lo phototrophic microorganisms. Three natural biocides were selecled: (i) cells free filtrate of bacterium Burkholderia gladioli pv. agaricicola ICMP 11096 strain (Bga); (ii) cells free filtrate of fungus Trichoderma harzianum strain T-22; and (iii) glycoalkaloids extracts from unripe berries of Solanum nigrum (European Black Nightshade), a spontaneous plant belongs to Solanaceae family. During three months of incubalion, spectrophotometric deterrnination of chlorophyll a was monthly pertormed in order to evaluate the total amount of photosynthetie biomass. In addition, the efficiency as biocides of the metabolites tested was assessed by digital image analysis (Principal Components Analysis) for the quantification of surtaee covered areas, and by field emission scanning electron microscopy. Preliminary results revealed that the glycoalkaloids are the mosl efficient biocidal treatment, whereas the Trichoderma harzianum filtrate haslened Ihe development of pholotrophic microorganisms on the stone probes. As a conclusion, the use of natural biocides could be a greater safe and eeo-friendly alternative Ihan most common biocides. They can also be used as a preventive method to minimize biodeterioration and thereafter reduce maintenance interval and costs.

Benavente, David et al.-- 4 pages, 3 figures, 4 references.-- Proceedings of the International Congress on Science and Technology for the Conservation of Cultural Heritage, held 2-5 october, Santiago de Compostela, España., The Necropolis of Carmona (Seville, Spain), used during the first and second centuries AD, is one of the most significant Roman burial sites in southern Spain. With more than 600 tombs, the Circular Mausoleum is one of the best examples of a tomb affected by different decay mechanisms. The alteration patterns are varied and abundant, including host-rock fragmentation, loss of materials (mineral disintegration), surface modifications (efflorescences, crusts of various typologies) and biological colonization (mainly bacteria, algae and lichens). The different pathologies observed are discussed to the light of environmental parameters., The authors acknowledge funding from the Consejería de Cultura (project "Estudio integral del estado de conservación del Conjunto Arqueológico de Carmona") and Consejería de Innovacion, Ciencia y Empresa (project P06-RNM-2318).

4 pages, 1 figure, 10 references.-- Proceedings of the International Congress on Science and Technology for the Conservation of Cultural Heritage, held 2-5 october, Santiago de Compostela, España., Diesel soot, an important contributor to atmospheric aerosols, consists of a complex mixture of compounds. However, a very limited knowledge on the organic composition of aerosol and the water soluble fraction exists. A considerable portion of polar (oxygenated) organic compounds remained unanalysed, and additional analyses are needed to identify the polar compounds. Column fractionation of a diesel soot results in the obtaining of a methanol-soluble polar fraction enriched in aromatic polycarboxylic acids. This analysis provides a comprehensive dataset and important clues for solving the chemical nature of the polar (oxygenated) aerosol fraction and for identifying the polar compounds deposited on the surfaces of historic monuments., Funded by CSIC 200830023 project.

This work reports on the characterization of Roman mosaic samples from Carmona and Italica (Spain). A physico-chemical study of both glass tesserae and mortar fragments to determine their composition, to evaluate their state of conservation and to study their production technology was carried out. Samples were characterized by means of a binocular microscope, SEMEDS, visible spectrophotometry, XRD and petrographic analysis. The tesserae were made from soda lime silicate glass, even though one of them showed high contents of lead and copper oxides. The samples from Carmona showed deterioration pathologies associated to the humidity affecting the mosaic during burial, while those from Italica presented traces of biodeterioration. The data also indicated that the glass used in the tesserae had a lower technical quality than that used in tableware pieces of similar chronology., The authors acknowledge partial financial support from programs Consolider Ingenio 2010 Ref. TCP-CSD 2007- 00058 and Geomateriales ref. S2009/MAT-1629, as well as professional support from TECHNO-HERITAGE (Network of Science and Technology for Heritage Conservation). T.P. acknowledges a pre-doctoral FPU grant from the Spanish Ministry of Science and Innovation (MICINN).

Electronic Newsletter. CSIC Thematic Network on Cultural Heritage and Network on Science and Technology for the Conservation of Cultural Heritage Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Apartado de Correos 1052, 41080 Sevilla (Spain), A comment “The lessons of Lascaux” was published in the issue nº 10 (July 2005) of COALITION. Further, the problems of this cave were widely discussed in the media.

Prehistoric cave paintings, some of them dating back 20,000 years, are a unique legacy of considerable importance. Because caves containing such paintings, particularly Altamira in Spain and Lascaux in France, have drawn millions of visitors and attract considerable cultural and political attention, their preservation is a priority (Fig. 1). Prehistoric paintings are exposed to a variety of potentially damaging physical, chemical, and biological factors. Among the latter, microorganisms are of special importance through colony and biofilm formation. In some cases, microorganisms may damage or destroy paintings by using them as substrates during growth, by producing destructive metabolites, or by covering them. Hence, conservators, management agencies, and the general public share concerns about preserving these fragile works of art. Investigating the damaging effects of microorganisms on cave paintings involves two basic steps. First, investigators survey the diversity of microorganisms that are associated with paintings on cave walls to understand which components within those microbial communities are causing deterioration. Second, investigators try to uncover the metabolic capabilities of these microorganisms to learn which members carry a serious risk for that artwork., The authors acknowledge financial support from a the Spanish Ministry of Education and Science projects CGL2006–11561/ BTE, CGL2006–07424/BOS and the I3 program project 200640I197 (cofinanced by FEDER funds), Spanish Ministry of Culture (Contract 31321000710T), and the Government of Aragon project PM055/2006.

5 pages, 1 figure, 2 tables, 14 references. Electronic Newsletter. CSIC Thematic Network on Cultural Heritage and Network on Science and Technology for the Conservation of Cultural Heritage Instituto de Recursos Naturales y Agrobiología de Sevilla, CSIC, Apartado de Correos 1052, 41080 Sevilla (Spain)., The study of microorganisms involved in deterioration of prehistoric paintings is of great importance to preserve these singular samples of cultural heritage. This study presents, as an example, results from a research carried out in Altamira Cave (Cantabria, Spain). Altamira Cave contains numerous and well known paintings from the Upper Palaeolithic, dated back around 15,000 years. This work focused in understanding the microorganisms inhabiting this singular system and the potential consequences of its microbial diversity for conservation of these valuable paintings., The authors acknowledge financial support from the Spanish Ministry of Education and Science (project CGL2006-07424/BOS) and the Spanish Ministry of Culture.

Póster presentado a la citada conferencia, celebrada del 28 noviembre-1 diciembre, 2007, Sevilla, España.